blob: 181433bf33ff1f590cdf9c4dea2875ab0a0af77f [file] [log] [blame]
#!/bin/bash -x
# Copyright 2016 The Bazel Authors. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# This script collects code coverage data for C++ sources, after the tests
# were executed.
#
# Bazel C++ code coverage collection support is poor and limited. There is
# an ongoing effort to improve this (tracking issue #1118).
#
# Bazel uses the lcov tool for gathering coverage data. There is also
# an experimental support for clang llvm coverage, which uses the .profraw
# data files to compute the coverage report.
#
# This script assumes the following environment variables are set:
# - COVERAGE_DIR Directory containing metadata files needed for
# coverage collection (e.g. gcda files, profraw).
# - COVERAGE_MANIFEST Location of the instrumented file manifest.
# - COVERAGE_GCOV_PATH Location of gcov. This is set by the TestRunner.
# - COVERAGE_GCOV_OPTIONS Additional options to pass to gcov.
# - ROOT Location from where the code coverage collection
# was invoked.
#
# The script looks in $COVERAGE_DIR for the C++ metadata coverage files (either
# gcda or profraw) and uses either lcov or gcov to get the coverage data.
# The coverage data is placed in $COVERAGE_OUTPUT_FILE.
# Checks if clang llvm coverage should be used instead of lcov.
function uses_llvm() {
if stat "${COVERAGE_DIR}"/*.profraw >/dev/null 2>&1; then
return 0
fi
return 1
}
# Returns 0 if gcov must be used, 1 otherwise.
function uses_gcov() {
[[ "$GCOV_COVERAGE" -eq "1" ]] && return 0
return 1
}
function init_gcov() {
# Symlink the gcov tool such with a link called gcov. Clang comes with a tool
# called llvm-cov, which behaves like gcov if symlinked in this way (otherwise
# we would need to invoke it with "llvm-cov gcov").
# For more details see https://llvm.org/docs/CommandGuide/llvm-cov.html.
GCOV="${COVERAGE_DIR}/gcov"
if [ ! -f "${COVERAGE_GCOV_PATH}" ]; then
echo "GCov does not exist at the given path: '${COVERAGE_GCOV_PATH}'"
exit 1
fi
# When using a tool from a toolchain COVERAGE_GCOV_PATH will be a relative
# path. To make it work on different working directories it's required to
# convert the path to an absolute one.
COVERAGE_GCOV_PATH_ABS="$(cd "${COVERAGE_GCOV_PATH%/*}" && pwd)/${COVERAGE_GCOV_PATH##*/}"
ln -s "${COVERAGE_GCOV_PATH_ABS}" "${GCOV}"
}
# Computes code coverage data using the clang generated metadata found under
# $COVERAGE_DIR.
# Writes the collected coverage into the given output file.
function llvm_coverage() {
local output_file="${1}"; shift
export LLVM_PROFILE_FILE="${COVERAGE_DIR}/%h-%p-%m.profraw"
"${COVERAGE_GCOV_PATH}" merge -output "${output_file}" \
"${COVERAGE_DIR}"/*.profraw
}
# Generates a code coverage report in gcov intermediate text format by invoking
# gcov and using the profile data (.gcda) and notes (.gcno) files.
#
# The profile data files are expected to be found under $COVERAGE_DIR.
# The notes file are expected to be found under $ROOT.
#
# - output_file The location of the file where the generated code coverage
# report is written.
function gcov_coverage() {
local output_file="${1}"; shift
# We'll save the standard output of each the gcov command in this log.
local gcov_log="$output_file.gcov.log"
# Copy .gcno files next to their corresponding .gcda files in $COVERAGE_DIR
# because gcov expects them to be in the same directory.
while read -r line; do
if [[ ${line: -4} == "gcno" ]]; then
gcno_path=${line}
local gcda="${COVERAGE_DIR}/$(dirname ${gcno_path})/$(basename ${gcno_path} .gcno).gcda"
# If the gcda file was not found we skip generating coverage from the gcno
# file.
if [[ -f "$gcda" ]]; then
# gcov expects both gcno and gcda files to be in the same directory.
# We overcome this by copying the gcno to $COVERAGE_DIR where the gcda
# files are expected to be.
if [ ! -f "${COVERAGE_DIR}/${gcno_path}" ]; then
mkdir -p "${COVERAGE_DIR}/$(dirname ${gcno_path})"
cp "$ROOT/${gcno_path}" "${COVERAGE_DIR}/${gcno_path}"
fi
# Invoke gcov to generate a code coverage report with the flags:
# -i Output gcov file in an intermediate text format.
# The output is a single .gcov file per .gcda file.
# No source code is required.
# -o directory The directory containing the .gcno and
# .gcda data files.
# "${gcda"} The input file name. gcov is looking for data files
# named after the input filename without its extension.
# gcov produces files called <source file name>.gcov in the current
# directory. These contain the coverage information of the source file
# they correspond to. One .gcov file is produced for each source
# (or header) file containing code which was compiled to produce the
# .gcda files.
# Don't generate branch coverage (-b) because of a gcov issue that
# segfaults when both -i and -b are used (see
# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84879).
"${GCOV}" -i $COVERAGE_GCOV_OPTIONS -o "$(dirname ${gcda})" "${gcda}"
# Append all .gcov files in the current directory to the output file.
cat *.gcov >> "$output_file"
# Delete the .gcov files.
rm *.gcov
fi
fi
done < "${COVERAGE_MANIFEST}"
}
function main() {
init_gcov
# If llvm code coverage is used, we output the raw code coverage report in
# the $COVERAGE_OUTPUT_FILE. This report will not be converted to any other
# format by LcovMerger.
# TODO(#5881): Convert profdata reports to lcov.
if uses_llvm; then
BAZEL_CC_COVERAGE_TOOL="PROFDATA"
fi
# When using either gcov or lcov, have an output file specific to the test
# and format used. For lcov we generate a ".dat" output file and for gcov
# a ".gcov" output file. It is important that these files are generated under
# COVERAGE_DIR.
# When this script is invoked by tools/test/collect_coverage.sh either of
# these two coverage reports will be picked up by LcovMerger and their
# content will be converted and/or merged with other reports to an lcov
# format, generating the final code coverage report.
case "$BAZEL_CC_COVERAGE_TOOL" in
("GCOV") gcov_coverage "$COVERAGE_DIR/_cc_coverage.gcov" ;;
("PROFDATA") llvm_coverage "$COVERAGE_DIR/_cc_coverage.profdata" ;;
(*) echo "Coverage tool $BAZEL_CC_COVERAGE_TOOL not supported" \
&& exit 1
esac
}
main